1. Field of the Invention
This invention relates to winders for winding an on-coming web of material into a wound roll. More particularly, this invention relates to a two-drum winder, such as is used in the papermaking industry for winding a traveling paper web into a roll of paper. Still more particularly, this invention relates to a two-drum type of papermaking winder wherein the wound roll is supported on a looped, resilient belt over the support drums.
2. Description of the Prior Art
The two-drum type of winder, wherein the wound paper roll is supported by a pair of parallel, essentially horizontally disposed support drums, is well-known in the papermaking art. Also known is the use of support drums having either a resilient cover or a looped resilient belt disposed over the surfaces of the support drums. Finally, it is also known to support the wound paper roll by means of a separate tensioned belt on either side of the roll as it is being wound. Examples of such apparatus is shown and described in British Patent No. 417,769 and U.S. Pat. No. 3,098,619.
Improvements in two-drum types of winders which utilize a belt have recently been introduced into the market and have been patented. Such apparatus is generally characterized by utilizing a fixedly mounted, metal-surfaced support drum to support the paper roll being wound on one side of the two-drum configuration while the other side of the roll being wound is supported by a nip with either a belt-wrapped drum, or by a tensioned belt spanning spaced support drums, generally with one or both of the support drums also supporting the wound roll by nipping engagement therewith beneath the tensioned belt. Examples of such apparatus are shown and described in U.S. Pat. Nos. 4,842,209; 4,883,233 and 4,921,183.
However extensive the teaching of the use of a belt in conjunction with the support drums in a two-drum type of papermaking winder has become, there are still some shortcomings in this technology which have not been overcome by those skilled in the art. Thus, while the use of a pair of spaced, tensioned belts, each looped over a pair of spaced support drums, to support a paper web roll on either side of its center is known, as is the use of a single looped belt disposed about a pair of support drums, the use of a single looped belt in conjunction with a pair of spaced support drums for initially nipping a core with the belt and winding an on-coming paper web onto the core and into a complete wound paper roll while coordinating the belt tension has not heretofore been envisioned.
The more elaborate configurations which utilize a fixedly mounted metal support drum to support the wound roll on one side while utilizing a laterally displaceable support drum wrapped by a belt on the other side still do not permit the flexibility and range of operating characteristics and wound roll parameters, particularly at the early stages of wound roll formation, which are desired and necessary in today's competitive market where wound rolls having diameters of 60 inches (152.4 cm), or larger, are required to meet the customer's specifications.
What is characteristic of all prior belted drum winder configurations is their limited ability to maintain web tension and nip pressure, or a combination of both, which is sufficiently flexible in its range throughout the winding operation from when the newly severed web is brought into winding engagement with a new core, or reel spool, to the time when the wound roll reaches its desired maximum diameter. Specifically, the prior belted support drum arrangements did not engage the surface of the wound roll initially solely with a resilient belt, and they did not maintain engagement and support of the wound paper roll solely with the resilient belt during the entire winding process while coordinating the wound roll support with variable belt tension and the rider roll nip force.